Fix frozen terminals after split churn (#12)

* Fix blank terminal after split operations and add visual tests

## Blank Terminal Fix
- Add `needsRefreshAfterWindowChange` flag in GhosttyTerminalView
- Force terminal refresh when view is added to window, even if size unchanged
- Add `ghostty_surface_refresh()` call in attachToView for same-view reattachment
- Add debug logging for surface attachment lifecycle (DEBUG builds only)

## Bonsplit Migration
- Add bonsplit as local Swift package (vendor/bonsplit submodule)
- Replace custom SplitTree with BonsplitController
- Add Panel protocol with TerminalPanel and BrowserPanel implementations
- Add SidebarTab as main tab container with BonsplitController
- Remove old Splits/ directory (SplitTree, SplitView, TerminalSplitTreeView)

## Visual Screenshot Tests
- Add test_visual_screenshots.py for automated visual regression testing
- Uses in-app screenshot API (CGWindowListCreateImage) - no screen recording needed
- Generates HTML report with before/after comparisons
- Tests: splits, browser panels, focus switching, close operations, rapid cycles
- Includes annotation fields for easy feedback

## Browser Shortcut (⌘⇧B)
- Add keyboard shortcut to open browser panel in current pane
- Add openBrowser() method to TabManager
- Add shortcut configuration in KeyboardShortcutSettings

## Screenshot Command
- Add 'screenshot' command to TerminalController for in-app window capture
- Returns OK with screenshot ID and path

## Other
- Add tests/visual_output/ and tests/visual_report.html to .gitignore

* Add browser title subscription and set tab height to 30px

- Subscribe to BrowserPanel.$pageTitle changes to update bonsplit tabs
- Update tab titles in real-time as page navigation occurs
- Clean up subscriptions when panels are removed
- Set bonsplit tab bar and tab height to 30px (in submodule)

* Fix socket API regressions in list_surfaces, list_bonsplit_tabs, focus_pane

- list_surfaces: Remove [terminal]/[browser] suffix to keep UUID-only format
  that clients and tests expect for parsing
- list_bonsplit_tabs --pane: Properly look up pane by UUID instead of
  creating a new PaneID (requires bonsplit PaneID.id to be public)
- focus_pane: Accept both UUID strings and integer indices as documented

* Fix browser panel stability and keyboard shortcuts

- Prevent WKWebView focus lifecycle crashes during split/view reshuffles
- Match bracket shortcuts via keyCode (Cmd+Shift+[ / ], Cmd+Ctrl+[ / ])
- Support Ghostty config goto_split:* keybinds when WebView is focused
- Add focus_webview/is_webview_focused socket commands and regression tests
- Rename SidebarTab to Workspace and update docs

* Make ctrl+enter keybind test skippable

Skip when the Ghostty keybind isn't configured or when osascript can't send keystrokes (no Accessibility permission), so VM runs stay green.

* Auto-focus browser omnibar when blank

When a browser surface is focused but no URL is loaded yet, focus the address bar instead of the WKWebView.

* Stabilize socket surface indexing

* Focus browser omnibar escape; add webview keybind UI tests

- Escape in omnibar now returns focus to WKWebView\n- Add UI tests for Cmd+Ctrl+H pane navigation with WebKit focused (including Ghostty config)\n- Avoid flaky element screenshots in UpdatePillUITests on the UTM VM

* Fix browser drag-to-split blanks and socket parsing

* Fix webview-focused shortcuts and stabilize browser splits

- Match ctrl/shift shortcuts by keyCode where needed (Ctrl+H, bracket keys)
- Load Ghostty goto_split triggers reliably and refresh on config load
- Add debug socket helpers: set_shortcut + simulate_shortcut for tests
- Convert browser goto_split/keybind tests to socket-based injection (no osascript)
- Bump bonsplit for drag-to-split fixes

* Fix split layout collapse and harden socket pane APIs

* Stabilize OSC 99 notification test timing

* Fix terminal focus routing after split reparent

* Support simulate_shortcut enter for focus routing test

* Stabilize terminal focus routing test

* Fix frozen new terminal tabs after many splits

* Fix frozen new terminal tabs after splits

* Fix terminal freeze on launch/new tabs

* Update ghostty submodule

* Fix terminal focus/render stalls after split churn

* Fix nested split collapsing existing pane

* Fix nested split collapse + stabilize new-surface focus

* Update bonsplit submodule

* Fix SIGINT test flake

* Remove bonsplit tab-switch crossfade

* Remove PROJECTS.md

* Remove bonsplit tab selection animation

* Ignore generated test reports

* Middle click closes tab

* Revert unintended .gitignore change

* Fix build after main merge

* Revert "Fix build after main merge"

This reverts commit 16bf9816d0856b5385d52f886aa5eb50f3c9d9a4.

* Revert "Merge remote-tracking branch 'origin/main' into fix/blank-terminal-and-visual-tests"

This reverts commit 7c20fb53fd71fea7a19a3673f2dd73e5f0c783c4, reversing
changes made to 0aff107d787bc9d8bbc28220090b4ca7af72e040.

* Remove tab close fade animation

* Use terminal.fill icon

* Make terminal tab icon smaller

* Match browser globe tab icon size

* Bonsplit: tab min width 48 and tighter close button

* Bonsplit: smaller tab title font

* Show unread notification badge in bonsplit tabs and improve UI polish

Sync unread notification state to bonsplit tab badges (blue dot).
Improve EmptyPanelView with Terminal/Browser buttons and shortcut hints.
Add tooltips to close tab button and search overlay buttons.

* Fix reload.sh single-instance safety check on macOS

Replace GNU-only `ps -o etimes=` with portable `ps -o etime=` and
parse the dd-hh:mm:ss format manually for macOS compatibility.

* Centralize keyboard shortcut definitions into Action enum

Replace per-shortcut boilerplate with a single Action enum that holds
the label, defaults key, and default binding for each shortcut. All
call sites now use shortcut(for:). Settings UI is data-driven via
ForEach(Action.allCases). Titlebar tooltips update dynamically when
shortcuts are changed. Remove duplicate .keyboardShortcut() modifiers
from menu items that are already handled by the event monitor.

* Fix WKWebView consuming app menu shortcuts and close panel confirmation

Add CmuxWebView subclass that routes key equivalents through the main
menu before WebKit, so Cmd+N/Cmd+W/tab switching work when a browser
pane is focused. Fix Cmd+W close-panel path: bypass Bonsplit delegate
gating after the user confirms the running-process dialog by tracking
forceCloseTabIds. Add unit tests (CmuxWebViewKeyEquivalentTests) and
UI test scaffolding (MenuKeyEquivalentRoutingUITests) with a new
cmux-unit Xcode scheme.

* Update CLAUDE.md and PROJECTS.md with recent changes

CLAUDE.md: enforce --tag for reload commands, add cleanup safety rules.
PROJECTS.md: log notification badge, reload.sh fix, Cmd+W fix, WebView
key equiv fix, and centralized shortcuts work.

* Keep selection index stable on close

* Add concepts page documenting terminology hierarchy

New docs page explaining Window > Workspace > Pane > Surface > Panel
hierarchy with aligned ASCII diagram. Updated tabs.mdx and splits.mdx
to use consistent terminology (workspace instead of tab, surface
instead of panel) and corrected outdated CLI command references.

* Update bonsplit submodule

* WIP: improve split close stability and UI regressions

* Close terminal panel on child exit; hide terminal dirty dot

* Fix split close/focus regressions and stabilize UI tests

* Add unread Dock/Cmd+Tab badge with settings toggle

* Fix browser-surface shortcuts and Cmd+L browser opening

* Snapshot current workspace state before regression fixes

* Update bonsplit submodule snapshot

* Stabilize split-close regression capture and sidebar resize assertions

* Change default Show Notifications shortcut from Cmd+Shift+I to Cmd+I

* Fix update check readiness race, enable release update logging, and improve checking spinner

* Restore terminal file drop, fix browser omnibar click focus, and add panel workspace ID mutation for surface moves

* Add Cmd+digit workspace hints, titlebar shortcut pills, sidebar drag-reorder, and workspace placement settings

* Add v2 browser automation API, surface move/reorder commands, and short-handle ref system to TerminalController

* Add CLI browser command surface, --id-format flag, and move/reorder commands

* Extend test clients with move/reorder APIs, ref-handle support, and increased timeouts

* Harden test runner scripts with deterministic builds, retry logic, and robust socket readiness

* Stabilize existing test suites with focus-wait helpers, increased timeouts, and API shape updates

* Add terminal file drop e2e regression test

* Add v2 browser API, CLI ref resolution, and surface move/reorder test suites

* Add unit tests for shortcut hints, workspace reorder, drop planner, and update UI test stabilization

* Add cmux-debug-windows skill with snapshot script and agent config

* Update project docs: mark browser parity and move/reorder phases complete, add parallel agent workflow guidelines

* Update bonsplit submodule: re-entrant setPosition guard, tab shortcut hints, and moveTab/reorderTab API

* Add browser agent UX improvements: snapshot refs, placement reuse, diagnostics, and skill docs

- Upgrade browser.snapshot to emit accessibility tree text with element refs (eN)
- Add right-sibling pane reuse policy for browser.open_split placement
- Add rich not_found diagnostics with retry logic for selector actions
- Support --snapshot-after for post-action verification on mutating commands
- Allow browser fill with empty text for clearing inputs
- Default CLI --id-format to refs-first (UUIDs opt-in via --id-format uuids|both)
- Format legacy new-pane/new-surface output with short surface refs
- Add skills/cmuxterm-browser/ and skills/cmuxterm/ end-user skill docs
- Add regression tests for placement policy, snapshot refs, diagnostics, and ID defaults

* Update bonsplit submodule: keep raster favicons in color when inactive

Sources/WindowToolbarController.swift

@@ -2,6 +2,7 @@ import AppKit
 import Combine
 import SwiftUI
 
+@MainActor
 final class WindowToolbarController: NSObject, NSToolbarDelegate {
     private let commandItemIdentifier = NSToolbarItem.Identifier("cmux.focusedCommand")
     private let updateItemIdentifier = NSToolbarItem.Identifier("cmux.updatePill")
@@ -11,8 +12,8 @@ final class WindowToolbarController: NSObject, NSToolbarDelegate {
 
     private var commandLabels: [ObjectIdentifier: NSTextField] = [:]
     private var observers: [NSObjectProtocol] = []
-    private var updateCancellables: [ObjectIdentifier: AnyCancellable] = [:]
-    private var updateHostingViews: [ObjectIdentifier: NSView] = [:]
+    private var updateSizeCancellables: [ObjectIdentifier: AnyCancellable] = [:]
+    private var updateViewConstraints: [ObjectIdentifier: (width: NSLayoutConstraint, height: NSLayoutConstraint)] = [:]
 
     init(updateViewModel: UpdateViewModel) {
         self.updateViewModel = updateViewModel
@@ -23,7 +24,7 @@ final class WindowToolbarController: NSObject, NSToolbarDelegate {
         for observer in observers {
             NotificationCenter.default.removeObserver(observer)
         }
-        for cancellable in updateCancellables.values {
+        for cancellable in updateSizeCancellables.values {
             cancellable.cancel()
         }
     }
@@ -59,7 +60,9 @@ final class WindowToolbarController: NSObject, NSToolbarDelegate {
             queue: .main
         ) { [weak self] notification in
             guard let window = notification.object as? NSWindow else { return }
-            self?.attach(to: window)
+            Task { @MainActor in
+                self?.attach(to: window)
+            }
         })
     }
 
@@ -123,27 +126,43 @@ final class WindowToolbarController: NSObject, NSToolbarDelegate {
             return item
         }
 
+        #if DEBUG
         if itemIdentifier == updateItemIdentifier, let updateViewModel {
             let item = NSToolbarItem(itemIdentifier: itemIdentifier)
-            let hostingView = NonDraggableHostingView(rootView: UpdatePill(model: updateViewModel))
+            let view = NonDraggableHostingView(rootView: UpdatePill(model: updateViewModel))
             let key = ObjectIdentifier(toolbar)
-            item.view = hostingView
-            updateHostingViews[key] = hostingView
-
-            // Observe state changes to nudge the toolbar into re-laying-out
-            // the item when the pill's intrinsic content size changes.
-            updateCancellables[key]?.cancel()
-            updateCancellables[key] = updateViewModel.$state
+            item.view = view
+            sizeToolbarItem(for: key, hostingView: view)
+            updateSizeCancellables[key]?.cancel()
+            updateSizeCancellables[key] = updateViewModel.$state
                 .receive(on: DispatchQueue.main)
-                .sink { [weak hostingView] _ in
-                    DispatchQueue.main.async { [weak hostingView] in
-                        hostingView?.invalidateIntrinsicContentSize()
-                    }
+                .sink { [weak self, weak view] _ in
+                    guard let self, let view else { return }
+                    self.sizeToolbarItem(for: key, hostingView: view)
                 }
             return item
         }
+        #endif
 
         return nil
     }
 
+    private func sizeToolbarItem(for key: ObjectIdentifier, hostingView: NSView) {
+        hostingView.invalidateIntrinsicContentSize()
+        hostingView.layoutSubtreeIfNeeded()
+        let size = hostingView.fittingSize
+        hostingView.setFrameSize(size)
+        hostingView.setContentHuggingPriority(.required, for: .horizontal)
+        hostingView.setContentHuggingPriority(.required, for: .vertical)
+        hostingView.translatesAutoresizingMaskIntoConstraints = false
+        if let constraints = updateViewConstraints[key] {
+            constraints.width.constant = size.width
+            constraints.height.constant = size.height
+        } else {
+            let width = hostingView.widthAnchor.constraint(equalToConstant: size.width)
+            let height = hostingView.heightAnchor.constraint(equalToConstant: size.height)
+            NSLayoutConstraint.activate([width, height])
+            updateViewConstraints[key] = (width: width, height: height)
+        }
+    }
 }